Thank you for an important article, Max. The ethics around behavioural interventions is a topic that has been exercising me for quite some time too.

There are a few parts in your piece that I don’t quite understand, though. You say:

Firstly, in mandating that a nudge should not change an individual’s economic incentives, the authors claim to know what the nudgee’s economic incentives are to begin with.

I am not sure why mandating “no (change in) incentives”, T&S claim to know what the incentives are. Is it not possible to see this as a condition on any proposed changes in choice architecture — a requirement that they should not introduce any new economic incentives, or remove any incentives that were already there? In a technical sense you may be correct: you cannot know what exotic situation might function as an ‘economic’ incentive for me personally. But I think T&S’s intent is to limit the term ‘Nudge’ to interventions that do not offer a financial reward or penalty, or a significant change in the amount of effort. It is not unreasonable to consider placing fruit within immediate sight and cream cakes a few inches further a nudge to make people pick fruit; putting cream cakes on a different floor would require too much effort for this still to qualify as a nudge.

I would also say that this criticism…

The linguistic value of terms like ‘easy’ and ‘cheap’ depend on the context in which they exist and, as such, are inherently and inevitably subjective.

…is not entirely fair. I don’t think it is possible to define objective boundaries as to what is easy or cheap. Arguably, any change to the choice architecture will result in making one option cheaper or easier than the other (or vice versa). Of course it depends on the context, and of course the effect is subjective. But I think demanding objective robustness is missing the point, and is not going to help keeping behavioural interventions on the straight and narrow.

This, on the other hand, is a much more substantive criticism for me:

A nudge, they state, suggests the ‘best’ choice, while a mandate would seek to limit choice. However, empirical evidence shows that by altering the choice architecture, significantly more individuals are drawn towards the nudger’s desired outcome. Nudgees maintain full agency in theory, but nudgers effectively mandate choice because they know which option nudgees are most likely to choose.

I would stop short of saying, as you do, that nudgers mandate anything — the fact that the nudgees still have (and do exercise) a choice contradicts this. But the really fundamental problem with nudging arises when it pretends to be in the interest of the nudgee because it requires the nudger to know what is in the interest of the nudgee. This is problematic. It may be possible to ask an individual, but it is not possible to do this for a whole population, and then design a nudge that supports the preferences of every person in the population.

You may be interested in a recent story of mine (published less than a week before yours :-)), in which I argue that nudges, by definition, only apply to members of the target audience that have weak (or undefined) preferences. Everyone with a strong preference will be unaffected by interventions that qualify as nudges.

But I also argue that nudges cannot possible be positioned as interventions that are aimed to benefit individual members of the target population — for the simple reason that the nudgers are not in a position to know what would (or would) not be in their benefit. As you also say, financial literacy, retirement savings, organ donation etc are, arguably, to the benefit of society, but we cannot state categorically that they are necessarily to the benefit of every individual citizen. As long as nudges like these are (a) transparent and not surreptitious, and (b) established as interventions by the state to the benefit of the state and not by the state to benefit the individual, I don’t think there is all that much to be concerned about. Yes, as you say:

a nudger prioritises their own objectives over the moral implications

…or over any individual considerations of the individual nudgee. But such nudges are functionally not all that different from marketing and advertising campaigns.

Is there really a need for some formal framework that doesn’t already exist? You say that

policy-making affecting citizens in many countries around the world follows a direction [should be] is centred around the benefit of its adressees

But that seems to me an issue of policy-making, not of the tools to implement policy. Say we’re talking about a nudge to get job seekers to stick to their appointments a the job centre, or to their commitment to apply for suitable jobs. Do we need an ethical framework for nudges that aim to achieve that, any more than we need an ethical framework for the incentives that are often used to implement the government’s policies, such as penalties if a job seeker doesn’t turn up, or fails to apply for jobs?

Before we call for ethical constraints on nudges, we need to be clear about what possible ethical concerns could be about nudges.

Simply accepting that there are ways of influencing human behaviour without assessing the morality, analysing the (unintended) consequences and considering the impact is careless, and also dangerous.

This seems to me to be excessively alarmist. Nudges, as defined by T&S, have a limited effect on a limited group of people. They will indeed influence the behaviour of those people whose preferences are weak or undefined. But moral beliefs not normally weak preferences, so it is hard to see how a nudge might make someone act against their moral preferences — or indeed in any other way influence behaviour in an unethical way.

If you want to make people act against their own interest (and in yours), then you would not resort to nudges — you’d use far stronger (and more effective) persuasion techniques. If there are ethical frameworks to control such interventions, they would be more than adequate for nudges; and if there are none, then why worry about nudges?